Int J Sports Med 2003; 24(1): 9-14
DOI: 10.1055/s-2003-37251
Physiology & Biochemistry
© Georg Thieme Verlag Stuttgart · New York

Influence of Acute Moderate Hypoxia on Time to Exhaustion at vV˙O2max in Unacclimatized Runners

V.  L.  Billat1, 2 , P.  M.  Lepretre1 , R.  P.  Heubert1 , J.  P.  Koralsztein2 , F.  P.  Gazeau3
  • 1Laboratoire d'Etude de la Motricité Humaine, Faculté des Sciences du Sport, Université de Lille 2, Ronchin, France
  • 2Centre de Médecine du Sport Caisse Centrale des Activités Sociales, Paris, France
  • 3Personnal Trainer, Genève, Suisse
Further Information

Publication History

Accepted after revision: February 4, 2002

Publication Date:
12 February 2003 (online)

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Abstract

Eight unacclimatized long-distance runners performed, on a level treadmill, an incremental test to determine the maximal oxygen uptake (V˙O2max) and the minimal velocity eliciting V˙O2max (vV˙O2max) in normoxia (N) and acute moderate hypoxia (H) corresponding to an altitude of 2400 m (PIO2 of 109 mmHg). Afterwards, on separate days, they performed two all-out constant velocity runs at vV˙O2max in a random order (one in N and the other in H). The decrease in V˙O2max between N and H showed a great degree of variability amongst subjects as V˙O2max decreased by 8.9 ± 4 ml × min-1 × kg-1 in H vs. N conditions (-15.3 ± 6.3 % with a range from -7.9 % to -23.8 %). This decrease in V˙O2max was proportional to the value of V˙O2max (V˙O2max vs. delta V˙O2max N-H, r = 0.75, p = 0.03). The time run at vV˙O2max was not affected by hypoxia (483 ± 122 vs. 506 ± 148 s, in N and H, respectively, p = 0.37). However, the greater the decrease in vV˙O2max during hypoxia, the greater the runners increased their time to exhaustion at vV˙O2max (vV˙O2max N-H vs. tlim @vV˙O2max N-H, r = -0.75, p = 0.03). In conclusion, this study showed that there was a positive association between the extent of decrease in vV˙O2max, and the increase in run time at vV˙O2max in hypoxia.

References

V. Billat

Centre de Médecine du Sport CCAS

2 Avenue Richerand · 75010 Paris · France ·

Phone: +33-1-42020818

Fax: +33-1-42392083

Email: veronique.billat@wanadoo.fr